Agilent 1120

Amino acids were measured by HPLC according to Geiger et al. [63 (link)]. Approximately 60 mg root was placed in a screw cap tube and extracted sequentially for 15 min at 70] ^∘C with two 250 μl of 80% aqueous ethanol (buffered with 10 mM HEPES-KOH, pH 7.0), one 250 μl of 50% aqueous ethanol (buffered with 10 mM HEPES-KOH, pH 7.0) and one 250 μl of 10 mM HEPES-KOH, pH 7.0. The extract was centrifuged between each step (5 min, 14,000 g). The supernatants were combined and measured by HPLC (Agilent 1120, Palo Alto, CA, USA).

TBE-300C HSCCC equipment was used with three multilayer columns of a total of 300 mL (the diameter of the PTFE tube was 2.6 mm) and a 20 mL sample loop ( Tauto Biotech, Shanghai, China). An LC3050N integrated system was used to contact the HSCCC equipment, composed with a P3050N gradient pump and a UV3050N monitor (Beijing Tong Heng Innovation Technology Co., Ltd., Beijing, China). A DC-0506 low-constant-temperature bath was used to control the temperature at 30 °C. An Agilent 1120 with a Zobax SB C₁₈ column (5 μm, 250 mm × 4.6 mm, i.d.) was used for the sample detection process (Agilent Technologies, Santa Clara, CA, USA).